1. Field of the Invention
The present invention, in general relates to wheeled vehicles and, more particularly, to mobile types of devices that are powered by hand.
Hand powered mobile devices are generally known. For example, hand-powered rail carts for use on railroad tracks that have a central pivotal bar that is alternately raised and lowered are well known devices that can be powered by one or more persons simultaneously, but they are not practical for use on the street, especially by an individual operator. There are a number of reasons why these, and other prior art types of devices, are not well suited for individual use or for use on the street.
One such reason is because they tend to have large, cumbersome mechanisms and, as such, do not lend themselves well for use with smaller and lighter types of vehicles, for example, with two or three-wheeled types of scooters.
Recent developments in lightweight and durable materials have contributed to a great variety of small, folding types of scooters. These include two-wheeled types of mobile devices that are propelled by an individual standing on a platform of the scooter and kicking with one leg to propel the device.
This type of a kicking impulse makes for limited and inefficient use of the strengths of the individual and furthermore, because the individual is likely to use only a predominant leg for kicking, it fosters an uneven pattern of physical development (i.e., exercise).
It is desirable to be able to use the arms and hands of the individual to supply a motive force for a smaller, scooter-like, vehicle yet no lightweight and effective mechanism currently exists for doing so.
It is also desirable to use the muscle groups in the arms to supply this force. The arms have substantial muscle groups that, if an ergonomic system were to well utilize them, are well adapted to propel a scooter-like type of a vehicle.
Furthermore, doing so would strengthen the upper body while simultaneously providing a practical vehicle for short distance commuting.
Furthermore, prior types of hand powered devices do not provide a method for synchronizing the motion of both hands (and arms) of the user so that an alternating pushing and pulling motion, each arm at a time and in opposite relation to the other, would occur. Such a synchronized pattern of movement is optimally desired to provide the motive impulse.
A synchronized motion that ensures a particular relative position of one hand alternating back and forth when compared to the other is optimum for both power generation and also for comfort.
It is preferable to set up a routine whereby a recurrent pattern of motion occurs. This is one reason why pedaling a bicycle is so common. It involves a recurrent pattern of motion and that creates familiarity and the familiarity, in turn, fosters user comfort and confidence in the process and product.
Also, kicking a scooter provides a motive force (i.e., an impulse) and then the scooter coasts for a predetermined period of time until another kick can be accomplished. In other words the motive force is intermittent. It is desirable to be able to supply a more continuous motive force (i.e., one with a greater duty cycle whereby motive power is being supplied most of the time) to a scooter-like vehicle.
Accordingly, there exists today a need for a hand-powered vehicle that is lightweight, effectively transfers power derived from the hand and arm motion of the user into rotary motion that is used as a motive force, provides this force more evenly and continuously than by kicking, and which provides a positive and predictable relationship between two members that are alternately moved back and forth by the user.
Clearly, such an apparatus would be a useful and desirable device.
2. Description of Prior Art
Hand-powered vehicles are, in general, known. For example, the following patents describe various types of these devices:
U.S. Pat. No. 6,080,088 to Petersen et al., Jun. 27, 2000;
U.S. Pat. No. 5,050,864 to Pertramer, Sep. 24, 1991;
U.S. Pat. No. 5,007,655 to Hanna, Apr. 16, 1991;
U.S. Pat. No. 4,960,286 to Henson, Oct. 2, 1990;
U.S. Pat. No. 4,861,055 to Jones, Aug. 29, 1989;
U.S. Pat. No. 4,189,166 to Lindsey, Feb. 19, 1980;
U.S. Pat. No. 2,085,657 to Heisdorf, Jun. 29, 1937;
U.S. Pat. No. 1,735,665 to Ashby, Nov. 12, 1929;
U.S. Pat. No. 1,455,124 to Swinland, May 15, 1923;
U.S. Pat. No. 926,131 to McGowan, Jun. 29, 1909; and
U.S. Pat. No. 577,572 to Cross, Feb. 23, 1897.
While the structural arrangements of the above described devices, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.
It is an object of the present invention to provide a hand-powered vehicle that is lightweight.
It is also an important object of the invention to provide a hand-powered vehicle that is reliable to use.
Another object of the invention is to provide a hand-powered vehicle that includes a method for varying a mechanical advantage sufficient to change the force that is required in order to effectively impel the vehicle.
Still another object of the invention is to provide a hand-powered vehicle that includes a method for varying a gear ratio sufficient to change the force that is required to impel the vehicle.
Still yet another object of the invention is to provide a hand-powered vehicle that includes a method for varying the length of a moment arm sufficient to change the force that is required to impel the vehicle.
Yet another important object of the invention is to provide a hand-powered vehicle that provides a fixed and predictable relationship between two members that are alternately moved back and forth by a user.
Still yet another important object of the invention is to provide a hand-powered vehicle that includes a hand-powered scooter.
Still yet one further important object of the invention is to provide a hand-powered vehicle that eliminates xe2x80x9cdead spotsxe2x80x9d in the motive power supply process.
Briefly, hand-powered vehicle that is constructed in accordance with the principles of the present invention has a platform and at least two wheels that are attached to the platform. A user stands on the platform. An apparatus for converting an alternating back and forth motion by two arms of the user into a rotary motion is provided and is adapted to supply a torque to a drive wheel. The apparatus includes a first rack gear and a second rack gear and an idler gear operatively disposed therebetween. Accordingly, the first rack gear and the second rack gear move in opposite directions with respect to each other. The arms supply the necessary force to a pair of pivoting members sufficient to drive the first and second rack gears which in turn engage with a first and second coaster gear respectively. The coaster gears engage with the drive wheel sufficient to urge the vehicle forward. When a first arm is pulled rearward a remaining arm moves forward and when the remaining arm is pulled rearward the first arm moves forward. Accordingly, a back and forth repetitive motion of the arms is used to urge the vehicle forward and to provide a more continuous motive force.